In recent years large format video displays have become an accepted adjunct to public performances and public events. In sporting events held within stadiums, arenas and field houses, instant replay features and magnified views of the locus of sports action are an expected by the audience. Video displays are also used for popular music appearances, adding excitement, intimacy, and immediacy to the program material. In a business context, presentations at gatherings such as conventions and sales meetings are augmented by large video displays. Video is also now used routinely in institutional assemblies such as school graduations, corporate meetings, political speeches, and the like to dramatize the event. It is human nature to be attracted to a large format video display that presents color, sound and motion to the viewing audience. The large format display focuses on the center of action or attention, presenting an enlarged visualization of the important elements of the event that may not be visible to many of the attendees. Thus large video displays render live attendance even more immediate, and can recreate the feeling of live action at remote or delayed presentations.
Large video displays present unique problems in construction and maintenance. The displays are often placed in locations that are difficult to access, e.g., suspended from an arena ceiling, so that assembling and servicing the display is troublesome. The physics and economics of video displays dictate that a modular approach is optimal, in which a large number of modules are assembled, each presenting a portion of the total video image. The modules are heavy, and it is not easy to devise a support arrangement that is sufficiently lightweight to secure the modules in a stable matrix that can be suspended with absolute assurance of safety above a large number of people. The supports must also be capable of being lowered and rested on a surface for servicing without introducing stress on the components. Furthermore, each module should be accessible for quick servicing or replacement in the event of a component failure, so that the display may be repaired and operating with a minimum of down-time. A further requirement is ventilation within the assembled modules to remove the copious amounts of heat generated by the electronics and the video projection elements (generally high power CRT primary color projectors).
One example of a prior art video wall system is described in U.S. Pat. No. 4,866,530, issued Sep. 12, 1989 to Kevin Kalua. The present invention comprises an improvement over the prior art.